Modern electronics requires the use of high frequency and high speed connectors particularly for use in interconnecting circuitry on motherboards or backplanes and daughter cards or other circuit devices. These connectors require shielding or ground planes between the signal pins; e.g., stripline configuration, to provide high frequency signal integrity and minimize interference from outside sources. U.S. Pat. No. 4,975,084 discloses one such system provided with ground contacts between columns of signal contacts, the ground contacts of one connector having projecting blades and the mating ground contacts of the other connector including plates with cantilevered beams. The plates provide a shield between the columns of mated signal contacts and the cantilevered beams engage the blades to complete the ground circuits. The ground contacts of this connector are disposed within slots extending from the sidewall and partially across the respective housings and the connector includes an array of power, signal and ground contacts. This arrangement requires an amount of dielectric housing material to insulate between the adjacent contacts and to isolate the various circuits. For some applications, however, it is desirable to have a more highly dense array or grid of contact members, while maintaining the integrity between the lines. As the center line spacing between contact members in a row is decreased, the spacing between adjacent columns of contact members is likewise decreased, thereby necessarily reducing the amount of dielectric housing material between the members of the array. This in turn affects the electrical characteristics of the connector system and in particular reduces the impedance through the connector system. It is desirable, therefore, to have an electrical connector that provides a more dense array of contact members while maintaining the electrical characteristics associated with connectors having a less dense array of contact members.